#include<stdio.h>


int main()
{
    int *a;
    char *b;
    double *c;
    printf("a:%d\n",sizeof(a));
    printf("b:%d\n",sizeof(b));
    printf("c:%d\n",sizeof(c));
    int v=10;
    a=&v;
    printf("*a:%d\n",*a);
    *a=20;
    printf("v:%d\n",v);
    return 0;
}